test: ensure that directpath is enabled for direct path tests (#2263)

This should unblock #2033 which disables directpath by default

README.md

@@ -50,7 +50,7 @@ If you are using Maven without the BOM, add this to your dependencies:
 If you are using Gradle 5.x or later, add this to your dependencies:
 
 ```Groovy
-implementation platform('com.google.cloud:libraries-bom:26.41.0')
+implementation platform('com.google.cloud:libraries-bom:26.42.0')
 
 implementation 'com.google.cloud:google-cloud-bigtable'
 ```

google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/test_helpers/env/CloudEnv.java

@@ -134,8 +134,9 @@ private CloudEnv(
       dataSettings.stubSettings().setEndpoint(dataEndpoint);
     }
 
-    setupRemoteAddrInterceptor(dataSettings.stubSettings());
+    configureConnection(dataSettings.stubSettings());
     configureUserAgent(dataSettings.stubSettings());
+
     if (tracingCookie != null) {
       injectTracingCookie(tracingCookie, dataSettings.stubSettings());
     }
@@ -164,21 +165,24 @@ private static void injectTracingCookie(
                 .build());
   }
 
-  private void setupRemoteAddrInterceptor(StubSettings.Builder stubSettings) {
+  private void configureConnection(StubSettings.Builder stubSettings) {
     // Build an remote address restricting interceptor
     final ClientInterceptor interceptor;
+    boolean enableDirectPath = false;
 
     switch (getConnectionMode()) {
       case DEFAULT:
         // nothing special
         return;
       case REQUIRE_DIRECT_PATH:
+        enableDirectPath = true;
         interceptor =
             buildRemoteAddrInterceptor(
                 "DirectPath IPv4 or IPv6",
                 Predicates.or(DIRECT_PATH_IPV4_MATCHER, DIRECT_PATH_IPV6_MATCHER));
         break;
       case REQUIRE_DIRECT_PATH_IPV4:
+        enableDirectPath = true;
         interceptor =
             buildRemoteAddrInterceptor("DirectPath IPv4", Predicates.or(DIRECT_PATH_IPV4_MATCHER));
         break;
@@ -201,6 +205,10 @@ private void setupRemoteAddrInterceptor(StubSettings.Builder stubSettings) {
     final ApiFunction<ManagedChannelBuilder, ManagedChannelBuilder> oldConfigurator =
         channelProvider.getChannelConfigurator();
 
+    if (enableDirectPath) {
+      channelProvider.setAttemptDirectPath(true).setAttemptDirectPathXds();
+    }
+
     @SuppressWarnings("rawtypes")
     final ApiFunction<ManagedChannelBuilder, ManagedChannelBuilder> newConfigurator =
         new ApiFunction<ManagedChannelBuilder, ManagedChannelBuilder>() {